HTTP Request Smuggling in Apache Tomcat
Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.apache.tomcat:tomcat | >= 10.0.0-M1, < 10.0.7, >= 9.0.0-M1, < 9.0.48, >= 8.5.0, < 8.5.68 | 10.0.7, 9.0.48, 8.5.68 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-33037
- https://github.com/apache/tomcat/commit/05f9e8b00f5d9251fcd3c95dcfd6cf84177f46c8
- https://github.com/apache/tomcat/commit/19d11556d0db99df291df33605f137976d152475
- https://github.com/apache/tomcat/commit/3202703e6d635e39b74262e81f0cb4bcbe2170dc
- https://github.com/apache/tomcat/commit/45d70a86a901cbd534f8f570bed2aec9f7f7b88e
- https://github.com/apache/tomcat/commit/506134f957a4be2c5b4a9334f7b3435fc954dbc1
- https://github.com/apache/tomcat/commit/8874fa02e9b36baa9ca6b226c0882c0190ca5a02
- https://github.com/apache/tomcat/commit/a2c3dc4c96168743ac0bab613709a5bbdaec41d0
- https://github.com/apache/tomcat/commit/da0e7cb093cf68b052d9175e469dbd0464441b0b
- https://github.com/apache/tomcat/commit/eee0d024c1b3171560c92eaba79dd6eb8eb11bcd
- https://security.gentoo.org/glsa/202208-34
- https://security.netapp.com/advisory/ntap-20210827-0007
- https://tomcat.apache.org/security-10.html
- https://tomcat.apache.org/security-8.html
- https://tomcat.apache.org/security-9.html
- https://www.debian.org/security/2021/dsa-4952
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://lists.debian.org/debian-lts-announce/2021/08/msg00009.html
- https://lists.apache.org/thread/kovg1bft77xo34ksrcskh5nl50p69962
- https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262@%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b@%3Ccommits.tomee.apache.org%3E
- https://kc.mcafee.com/corporate/index?page=content&id=SB10366
- https://github.com/apache/tomcat
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N- Weakness (CWE)
CWE-444- Platform
- Java / Kotlin (Maven)
- Package
org.apache.tomcat:tomcat- Disclosed
- 13.08.2021
- Updated
- 11.10.2026 12:21
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4vww-mc66-62m6 - CC BY 4.0
Vulnerability history: org.apache.tomcat:tomcat
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 162
- First → latest
- 12.2018 08.2026
- Without a fix
- 20
- Exploited in attacks
- 1
Severity breakdown
- Critical 8
- High 40
- Medium 102
- Low 12
Disclosures per year
- 2018: 1
- 2019: 1
- 2020: 2
- 2021: 5
- 2022: 125
- 2023: 3
- 2024: 2
- 2025: 4
- 2026: 19
-
HTTP Request Smuggling in Apache Tomcat this entry
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